/Engine/Source/Runtime/MovieScene/Public/EntitySystem/MovieSceneEntityBuilder.h
// Add the data to an existing entity - will invalidate the entity builder EntityBuilder.MutateExisting(EntityManager, Existing);
template<typename... T> struct TEntityBuilder : public [UE::MovieScene::TEntityBuilderImpl< TMakeIntegerSequence< int, sizeof...(T)>, T... >](API\Runtime\MovieScene\EntitySystem\TEntityBuilderImpl)